Transition Metals refer to any elements found in the d-block of the periodic table. These are elements whose atoms have an incomplete d-subshell and can give rise to cations also with an incomplete subshell.

The d-subshell of transition metals is comprised of 5 orbitals, and as a consequence, a maximum of 10 d electrons may be present. The electronic structure of these transition elements can be commonly written as:

[]ns2(n-1)dm

Where,
[] indicates the noble gas that precedes this transition metal in the previous row
n indicates the number of main electron shells
s refers to the s-subshell
d refers to the d-subshell
m refers to the number of d-electrons

For example, iron (Fe) has the following electronic configuration:
[Ar]4s23d6

However, not all transition metals follow this configuration as there may be other structures which are more stable. For example, chromium (Cr) has the following electronic configuration:
[Ar]4s13d5

Cr has this particular configuration because two half-filled subshells are more stable than one filled subshell and one just partially filled. This also applies to the element copper (Cu), where its electronic structure is [Ar]4s13d10. Copper has one-half filled subshell and one fully filled subshell. Thus, understanding the complex properties of these d-block elements is crucial to understand their behavior.

For reaction 3b provide a completely balanced reaction and do it for number 6 also, my response for 3b was:
Cr(s) + 2HCl--> H2(g) + CrCl2+(aq)
My reaction may not be correct but the CrCl2+ is based off my results for the observation I got, which I don't believe are correct... The other two questions are what was the role o

See the attached files.
I am trying to understand the prelaboratory assignment, Can you make it any simpler than this?
The questions are attached on page 163.
Pre-Laboratory Assignment
Equilibrium constant
1. Write the equation and the equilibrium constant expression for the reaction under study in the experiment
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